You know what else would suffice plenty? Physical keys and mechanical locks. They worked (and still work) without electricity. The tech is mature and well-understood.
The reason for moving away from physical keys is that key management becomes a nightmare; you can't "revoke" a key without changing all the locks which is an expensive operation and requires distributing new keys to everyone else. Electronic access control solves that.
You might find Matt Blaze's paper on vulnerabilities in master-keyed physical locks interesting:
https://eprint.iacr.org/2002/160.pdf